While this season-ending outcome has been speculated for the last few weeks, the official announcement came after Nathan played catch with Twins’ pitching coach Rick Anderson Sunday morning.

This news raises the obvious question: Who will replace Nathan as Minnesota’s closer in 2010?

While it will be difficult to replace Nathan’s 246 saves and 2.04 ERA since 2004, the Twins do have a handful of in-house candidates.

Francisco Liriano was rumored to be a possibility for the Twins’ ninth inning duties, though manager Ron Gardenhire cleared the air on Saturday, saying Liriano will be used as a starter .

Matt Guerrier, Jose Mijares, and Pat Neshek have all proven to be capable relievers in the past, though the trio have a combined four career saves.

Jon Rauch has the most experience as a closer, as the 31-year-old only has 26 career saves. His 1.72 ERA over 15 2/3 innings with the Twins last year is likely to help his cause as well.

While Gardenhire has yet to make a decision, all signs point to Rauch being Minnesota’s closer on Opening Day.

Rauch has compiled 70-plus innings in four consecutive seasons, and his enormous 6'11", 291 pound frame should prove capable of handling the role. Expect the former White Sox farmhand to post an ERA in the 3.50 range and collect 30-plus saves for a Minnesota team that’s expected to contend for a second consecutive A.L. Central crown.